Bolt in cage test results

jasv11 · 10-27-2009, 12:11 PM

It didn't hold up too well apparently.

http://forums.themustangsource.com/s....php?p=5753663

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highjumpharry · 10-27-2009, 12:14 PM

wow... never skimp on weld in cages i guess

sourcandy · 10-27-2009, 12:19 PM

Kind of crappy they don't have close up pics of the cage meeting to the floor.

Even bolt in cages are suppose to have adequate flanges welded into the floor for just this reason. The floor on any car is not strong enough to simply bolt a cage to. It will punch right through it as shown. Welding the flanges helps in dispersing the loads so it is not focused on one small point.

Either way... those two are REALLY lucky!

dub c · 10-27-2009, 12:20 PM

aaah.
thanks a bunch for posting that up!
i can't believe they were unharmed!
is it weird that the inspector let that roll bar pass in whatever class that was racing in?

Mechie3 · 10-27-2009, 12:22 PM

Couple things:

What kind of roll cage? I know for Subies the Cusco 6pt is known to be for show only while the autopower bolt in's are meant for actual protection. What is a purchased or custom piece? If it was custom, they might have bolted it wherever without any structural testing.

IIRC, autopower (or maybe it's the SCCA?) requires that you put a 1/4" thick plate on the back side of where you bolt into to prevent the floor from ripping like that.

A welded cage could potentially do the same thing if the same size tube was welded to the same size floor patch it would still rip the floor. The force per area wouldn't change except for the added stress risers due to holes. I still believe welded > bolt in and some bolt ins > other bolt ins.

axelthrasher · 10-27-2009, 01:19 PM

Quote:

Originally Posted by Mechie3

IIRC, autopower (or maybe it's the SCCA?) requires that you put a 1/4" thick plate on the back side of where you bolt into to prevent the floor from ripping like that.

Back to the Mustang - if the roll bar/cage was mounted on or near the frame rails it more than likely would have been a lot more stable. I tried to find more pictures on the system they were using, but came up with nothing. Mechie is right in saying that if it had been welded in the same points that the bolt in was it would have done the same thing.

Xclusive · 10-27-2009, 01:33 PM

Seems to me the bar didn't fail, the floor did. If it was mounted properly or at least better, it may have worked.

imma_stocker · 10-27-2009, 01:38 PM

A poor weld-in cage does the same as a good bolt-in. To work, both require a large, well-placed flange to weld to the floor. Otherwise the bars will still punch through.

If you think welding that little circle around the base of the tube will hold up to a force like that, don't take passengers to prove me wrong.

Yotsuya · 10-27-2009, 01:43 PM

Reminds me of the midget wrestling face-skid gif.

69subaru360 · 10-27-2009, 01:50 PM

Poor choice of floor plate location more than roll bar fail. I have seen a drag car with weld in 6 point rollbar on the roof with the rollbar punched through the floor.

The last car I owned with a rollcage had 6x6 plates welded to the floor on top of the framerails with an additional tube going through the floor to welded and bolted in subframe connectors.

A bolt in cage could possible have survived this with proper floor plates.

sperry · 10-27-2009, 02:11 PM

Does this image imply they had to exit the car via the trunk?

sperry · 10-27-2009, 02:12 PM

White out · 10-27-2009, 02:21 PM

I'm surprised that wing didn't save them. . .

+1 for poor placement & plate choice.

Nick

White out · 10-27-2009, 02:21 PM

I'm surprised that wing didn't save them. . .

+1 for poor placement & plate choice.

Nick

KC · 10-27-2009, 02:47 PM

It's the Autopower Street Bar... not even a complete cage.

What does autopower say about this bar? (from another forum)

http://www.autopowerindustries.com/rollbars.asp

Quote:

STREET ROLL BAR
This roll bar will give your street car a performance look and style.

* In most cars rear seats and/or convertible top remain in place and useable.
* 4 point roll bar is made of 1.750 x .120 DOM mild steel tube.
* All necessary installation and mounting hardware with back-up plates is included.

Why anyone would think any roll *bar* can withstand an incident such as this is beyond me. Where they had it mounted... doesn't surprise me one bit why it punched through.

--kC

Element Tuning · 10-27-2009, 03:09 PM

Yeah a roll bar is inadequate for that type of incident. I would even think if it had larger welded plates it still would have pushed through the unibody. That's just too much weight/force being supported by two mounting points.

Bimmubishi · 10-27-2009, 03:17 PM

...Poor Ted Williams dead frozen head.

djosbun · 10-27-2009, 04:21 PM

HAHAHAHAHAHAHA (not at the crash, but at the Ted Williams quote).

Beaverboy · 10-27-2009, 04:33 PM

Quote:

Originally Posted by Element Tuning

Yeah a roll bar is inadequate for that type of incident. I would even think if it had larger welded plates it still would have pushed through the unibody. That's just too much weight/force being supported by two mounting points.

Even if the floor had held.. how much would a roll hoop without a diagonal brace put up with?

They're probably lucky the bar did what it did, rather than folding in half and piercing their heads/spines.

WgnWheel · 10-28-2009, 01:00 AM

Quote:

Originally Posted by Beaverboy

Even if the floor had held.. how much would a roll hoop without a diagonal brace put up with?

They're probably lucky the bar did what it did, rather than folding in half and piercing their heads/spines.

yeah, that scares me worse about this crash. high speed, heavy car landing flat on the roof would probably destroy that bar. it's unbelievable to me that they chose to install that thing in the first place.

imma_stocker · 10-28-2009, 02:09 AM

How did they escape without being crushed? The roof looks about even with the hood.

REX8 · 10-28-2009, 09:49 AM

Quote:

Originally Posted by WgnWheel

yeah, that scares me worse about this crash. high speed, heavy car landing flat on the roof would probably destroy that bar. it's unbelievable to me that they chose to install that thing in the first place.

Certainly better than nothing

REX8 · 10-28-2009, 09:49 AM

Quote:

Originally Posted by imma_stocker

How did they escape without being crushed? The roof looks about even with the hood.

Pushed to the side.

djosbun · 10-28-2009, 10:14 AM

Nice how they installed the slotted rotors on the wrong side of the car (the 'slots' should be pointing in the other direction).

Next time, hire a real racing shop to build your car.

neilschelly · 10-28-2009, 10:19 AM

Assuming they installed it correctly and that it resembles the AutoPower bar I've got, the bar should have had reinforcement plates for the outside. Each point would have been a bar welded to a decently large plate (3"x4" I think), with 3 strong bolts through that plate then the floor, then an identical plate under the car.

Without the diagonal, it's a show bar, as KC pointed out, but it appears to have held up as well as any 4-point roll bar would hold up in an accident of that nature. To have that much force pushing down on the plates, I wouldn't expect any floor to hold up that much better. They really are designed for the more typical rollover scenario which would have far less severe forces acting on the bar. It's unfortunate that in a fluke accident like this, the bar essentially became a very heavy and hard object to potentially hit the passengers in the cabin.

Anyway, I think it's fair to say that only a full cage would have faired better in this case, and it would still have been pretty severely damaged I imagine.
-N

10-27-2009, 12:11 PM	#1
jasv11 Scooby Newbie Member#: 117862 Join Date: Jun 2006 Chapter/Region: E. Canada Location: www.subiedrag.com Vehicle: 2006 STi 10.85@129.4 Innovative Tuning	Bolt in cage test results It didn't hold up too well apparently. http://forums.themustangsource.com/s....php?p=5753663 * Registered users of the site do not see these ads.

10-27-2009, 02:12 PM	#12
sperry Scooby Specialist Member#: 8636 Join Date: Jul 2001 Chapter/Region: BAIC Location: Reno, NV Vehicle: 94 SVX, 02 WRX, 01 F-250 SuperDuty	Last edited by sperry; 10-27-2009 at 02:14 PM. Reason: Ze servers are el slow!

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10-27-2009, 12:14 PM	#2
highjumpharry Scooby Newbie Member#: 166834 Join Date: Dec 2007 Chapter/Region: Tri-State Location: Jersey City Vehicle: 02 WRX WRB	wow... never skimp on weld in cages i guess

10-27-2009, 12:19 PM	#3
sourcandy Scooby Newbie Member#: 212410 Join Date: May 2009 Location: Houston, TX	Kind of crappy they don't have close up pics of the cage meeting to the floor. Even bolt in cages are suppose to have adequate flanges welded into the floor for just this reason. The floor on any car is not strong enough to simply bolt a cage to. It will punch right through it as shown. Welding the flanges helps in dispersing the loads so it is not focused on one small point. Either way... those two are REALLY lucky!

10-27-2009, 12:20 PM	#4
dub c NASIOC Supporter Member#: 145069 Join Date: Apr 2007 Chapter/Region: W. Canada Location: Calgary, Alberta, CANADA Vehicle: 2003 impreza wrx WRB	aaah. thanks a bunch for posting that up! i can't believe they were unharmed! is it weird that the inspector let that roll bar pass in whatever class that was racing in?

10-27-2009, 12:22 PM	#5
Mechie3 Scooby Guru Member#: 120152 Join Date: Jul 2006 Chapter/Region: MWSOC Location: Indy Vehicle: 2006 WRX, ESP 92 CNY Overall Pax Winner!	Couple things: What kind of roll cage? I know for Subies the Cusco 6pt is known to be for show only while the autopower bolt in's are meant for actual protection. What is a purchased or custom piece? If it was custom, they might have bolted it wherever without any structural testing. IIRC, autopower (or maybe it's the SCCA?) requires that you put a 1/4" thick plate on the back side of where you bolt into to prevent the floor from ripping like that. A welded cage could potentially do the same thing if the same size tube was welded to the same size floor patch it would still rip the floor. The force per area wouldn't change except for the added stress risers due to holes. I still believe welded > bolt in and some bolt ins > other bolt ins.

10-27-2009, 01:33 PM	#7
Xclusive Scooby Newbie Member#: 225704 Join Date: Oct 2009 Chapter/Region: Tri-State Location: Long Island, New York Vehicle: 1999 Outback Sport Green/Tan :(	Seems to me the bar didn't fail, the floor did. If it was mounted properly or at least better, it may have worked.

10-27-2009, 01:38 PM	#8
imma_stocker Scooby Specialist Member#: 97043 Join Date: Sep 2005 Chapter/Region: TXIC Location: elsewhere Vehicle: 08 310awhp STI 02 zero hp Z28	A poor weld-in cage does the same as a good bolt-in. To work, both require a large, well-placed flange to weld to the floor. Otherwise the bars will still punch through. If you think welding that little circle around the base of the tube will hold up to a force like that, don't take passengers to prove me wrong.

10-27-2009, 01:43 PM	#9
Yotsuya Scooby Guru Member#: 935 Join Date: Feb 2000 Chapter/Region: MWSOC Location: The City Vehicle: Tony Pond Fan Club	Reminds me of the midget wrestling face-skid gif.

10-27-2009, 01:50 PM	#10
69subaru360 Scooby Specialist Member#: 159682 Join Date: Sep 2007 Chapter/Region: Tri-State Location: Fleetwood, PA Vehicle: 1995 Impreza coupe 1969 360	Poor choice of floor plate location more than roll bar fail. I have seen a drag car with weld in 6 point rollbar on the roof with the rollbar punched through the floor. The last car I owned with a rollcage had 6x6 plates welded to the floor on top of the framerails with an additional tube going through the floor to welded and bolted in subframe connectors. A bolt in cage could possible have survived this with proper floor plates.

10-27-2009, 02:11 PM	#11
sperry Scooby Specialist Member#: 8636 Join Date: Jul 2001 Chapter/Region: BAIC Location: Reno, NV Vehicle: 94 SVX, 02 WRX, 01 F-250 SuperDuty	Does this image imply they had to exit the car via the trunk?

10-27-2009, 02:21 PM	#13
White out Scooby Guru Member#: 46277 Join Date: Oct 2003 Chapter/Region: MWSOC Location: Michigan Vehicle: H1 OpenTop Dodge Viper GTS ACR	I'm surprised that wing didn't save them. . . +1 for poor placement & plate choice. Nick

10-27-2009, 03:09 PM	#16
Element Tuning NASIOC Vendor Member#: 54918 Join Date: Feb 2004 Location: 10.76 best et 133mph best trap	Yeah a roll bar is inadequate for that type of incident. I would even think if it had larger welded plates it still would have pushed through the unibody. That's just too much weight/force being supported by two mounting points.

10-27-2009, 03:17 PM	#17
Bimmubishi Scooby Specialist Member#: 48713 Join Date: Nov 2003 Chapter/Region: NESIC Location: Dent Sport Garage Vehicle: 1988 Raider-1JZGTE DSG PLEASURE EVO DRIVER	...Poor Ted Williams dead frozen head.

10-27-2009, 04:21 PM	#18
djosbun NASIOC Supporter Member#: 202176 Join Date: Feb 2009 Chapter/Region: MWSOC Location: Hamilton, Ohio Vehicle: 2004 WRX wagon '07 Tribeca	HAHAHAHAHAHAHA (not at the crash, but at the Ted Williams quote).

10-28-2009, 02:09 AM	#21
imma_stocker Scooby Specialist Member#: 97043 Join Date: Sep 2005 Chapter/Region: TXIC Location: elsewhere Vehicle: 08 310awhp STI 02 zero hp Z28	How did they escape without being crushed? The roof looks about even with the hood.

10-28-2009, 10:14 AM	#24
djosbun NASIOC Supporter Member#: 202176 Join Date: Feb 2009 Chapter/Region: MWSOC Location: Hamilton, Ohio Vehicle: 2004 WRX wagon '07 Tribeca	Nice how they installed the slotted rotors on the wrong side of the car (the 'slots' should be pointing in the other direction). Next time, hire a real racing shop to build your car.

10-28-2009, 10:19 AM	#25
neilschelly NASIOC Supporter Member#: 94902 Join Date: Aug 2005 Chapter/Region: NESIC Location: Tyngsboro, MA Vehicle: 1999 Red OBS #28FSP 1992 Black BMW 325i	Assuming they installed it correctly and that it resembles the AutoPower bar I've got, the bar should have had reinforcement plates for the outside. Each point would have been a bar welded to a decently large plate (3"x4" I think), with 3 strong bolts through that plate then the floor, then an identical plate under the car. Without the diagonal, it's a show bar, as KC pointed out, but it appears to have held up as well as any 4-point roll bar would hold up in an accident of that nature. To have that much force pushing down on the plates, I wouldn't expect any floor to hold up that much better. They really are designed for the more typical rollover scenario which would have far less severe forces acting on the bar. It's unfortunate that in a fluke accident like this, the bar essentially became a very heavy and hard object to potentially hit the passengers in the cabin. Anyway, I think it's fair to say that only a full cage would have faired better in this case, and it would still have been pretty severely damaged I imagine. -N